Automatic zero and angle setting attachment for theodolites and the like.



W. G. WIESENER. AUTOMATIC ZERO AND ANGLE SETTING ATTACHMENT FOR THEODOLITES AND THE LIKE.

APPLICATION FILED OCT. 27, I913.

Patented Feb. 1, 1916.

2 SHEETS-SHEET I.

WITNESSES INI/ENTO? W. G. WIESENER. AUTOMATIC ZERO AND ANGLE SETTING ATTACHMENT FOR THEODOLITES AND THE LIKE.

APPLICATION FILED OCT. 27. 1913.

1, 1 69,897. Patented Feb. 1, 1916.

2 SHEETS-SHEET 2.

THE COLUMBIA PLANOURAPH 60., WASHINGTON, D. c.

-. STATES PATENT EFQE.

WILLIAM GEORGEWIESENER, or SYDNEY, NEW sooTH WALES, AUSTRALIA;

AUTQMATIC ZERO AND ANGLE SETTING ATTACHMENT FOR THEODOLITES AND THE LIKE.

Application filed October 27, 1913.

To all whom-it may] concern-z Be it known that 1, WILLIAM GEORGE for theodolites whereby the horizontal plate Vl'llil" is automatically set to' zero, 90 or any of the other'main angles on'the' di vided circle, the Object of the invention belng to provide a' means whereby the verni'er can be set at zero or to a desired angle such as 90 with constant accuracy thus eliminating the errors in setting that are always liable to occur when theinstrument has to be manip ulated.

The invention consists essentially in providing one or more adjustable fixed stops either on the index plate or divided circle plate according to the design of the theodolite; and a movable stop either on the divided circle plate'or indexplate, said mofvable stop being adapted tobe thrown in and out of the path of revolution of the fiXed stop or stops. projected into the path of one of the fixed stops a spring attachment is provided to bring the two stops into close contact, and

when in this position the Vernier is accurately set to the division on the dividedcircle corresponding to the fixed stop. But in order that the invention may be more 7 clearly understood reference will now be made to the-drawings"which acco'mp'any and form' p art of this specification? In the drawings" an attachment construct ed according to this inventionto automatically setthe zero of the Aver'nier" to either the 360 or'the 90 division on the divide'cl' circle is shown applied to a theod 'olite.

Figure 1,-is'a broken perspective view of a portion of the theodolite'showing the attachment in position. F ig. 2 is 'a" perspeo' tive view of the parts shown 111 Fig. 1, 1n an upright position andseparated to show the fixed stops on the underfa'ce of the index plate. Figs. 3 and 4, are sectional= elevations on planes 33 and 4-4 in Figs. land 2 respectively. Fig. 5, isa-plan'view on line 55 Fig. 4. Fig. 6, is a detail view of the adjustable stops.-

Specification of Letters Patent.

WVhen the movable stopis Patented Feb. 1, 1916. Serial No. 797,621.

lines in Fig. 3, the inoperative position of v the cam lever being that shown in full lines in F i'gs; 1, 2' and 3, in which it hangs from its pivotal connection 13*. On the bracket 7 is a verticalstoplO, see Fig. 3, adapted to be projected through an orifice in the plate 6 by meansot the spri'ng'lQ', and withdrawn therefrom eitherby a downward movement of the bracket by pressure on the thumbpiece 1 1,- or by the turning of the cam lever from the position shown infull lines in- Figs. 1 or 3' to that shown in dotted lines in the last mentioned figure. When the cam lever is turned from the position shown in full lines to the position shown in dotted lines,-in Fig. 3,-t-he cam surface 1'3 engages the plate 6 and causesthe downward movement of the bracket 7 which, when it has reached the limit-of its lowered position, has withdrawn the stop 10 from the orifice in the plate6. When the cam leveris turned' from the/position shown in dotted lines in Fig. 3 to the position shown in full lines in Figs. 1' and-3,

the bracket 7 is'returned'to its normal posi ti'on b y' the spring 12 toenable the stop 10to reenter the orifice in the plate 6.

Below the index plate 14 are two adjustable steps 15' and- 16' ha'v-ing' screw-threaded shanks" entered in the studs 15 and 16 re spectively, to permit of their adjustment, for

the purposehereinafter described, thestuds' being fixed tothe-indeX plate 1 1. The'free end of the stop 15 is positioned approximately beneaththe B-vernier and that of the stop 16 approXi'ma'tely 90 therefrom, and

block 21 on the index plate" 14. The free end of the carrier 18 passes loosely through the fiange22 of'theindeX plat'e'14- and the cam 24. The travel of the carrier 18 is con trolled by pins 25 taking in slots 26 in the carrier. When the spring 20 is drawn out of action by movement of the cam lever 24: the distance between the fixed stop 15 and the jaw 17 is suificient to allow the movable stop 10 when projected to pass easily between them, and when the spring 20 is released by the downward movement of the cam lever 2d the jaw 17 bearing on the stop 10 will bring it into spring contact with the fixed stop 15 in which position the'zero of the A vernier is accurately set to the 360 division on the divided circle plate 6. The action of the aw 17 in relation to the fixed stop 15 is reproduced as regards the fixed stop 16 by means of a bell crank 27 pivoted to the axis flange 14c at 28, and having the end of one arm 29 pivoted to the carrier 18 at 30, and the end o1 the other arm 81 which has a projection or jaw 32 juxtaposed to the fixed-stop 16.

The operation of setting the A Vernier to the 360 division on the divided circle is as follows :Firstusing the projecting cam lever 13 as a pointer bring it to approximately the center of the B vernier. Secondproject the movable stop 10 by lowering the cam lever 13. This brings the stop 10 between the fixed stop 15 and the jaw 17. Third-release the spring 19 by lowering the cam lever 2%. This brings the two stops into spring contact and sets the zero. The operation of setting the Zero of the A vernier to the 90 division is practically the same, except that the stop 10 is projected between the fixed stop 16 and the jaw 32, the approximate position to which cam lever 13 is placed in order to project the movable stop 10 between the stop 16 and the jaw 32 being indicated by a mark thus \i/ on the side of the index plate.

Having now fully described and ascertained the nature of my invention, what I claim as new and desire to secure by Letters Patent, is j 1. An automatic zero and angle-setting attachment for theodolites and the like comprising, an index plate and a divided circle plate, a fixed stop on one of said plates and a movable stop on the other plate to be moved into or out of operation with the fixed stop, and a spring operated jaw in juxtaposition to the fixed stop whereby it will engage the movable stop and bring it into spring contact with the fixed stop.

2. An automatic zero and angle-setting attachment for theodolites and the like comprising, an index plate and a divided circle plate, two fixed stops adjustable on one of said plates and a movable stop on the other plate to be selectively moved into or out of -operative relation with either one of the fixed stops, and two'movable spring operated jaws one in juxtaposition to each of said fixed stops whereby it will engage the movable stop and bring it into spring contact with its respective fixed stop.

a Anautomatic zero and angle-setting attachment for theodolites and the like comprising, an index plate and a divided circle plate, a fixed stop adjustable on one of said plates, a bracket hinged to the other of said plates, a movable stop pivoted to said bracket to engage said fixed stop, andmeans for bringing said movable stop into and out of operative relation with the fixed stop.

An automatic zero and angle-setting attachment for theodolites and the like com prising, an index plate and a divided circle plate, two fixed stops adjustable on one of said plates, a bracket hinged to the other of said plates, a movable stop pivoted to said bracket to engage said fixed stops, and

means for bringing said movable stop into and out of operative relation with the fixed iv stops. 6

5. An automatic zero and angle-setting cle plate, two fixed stops adjustable on one of said plates, a bracket hinged to the other of said plates, a movable stop, pivoted to said bracket to engage said fixed stops, means for bringing said movable stop into and out of operative relation with the fixed .90 attachment for theodolites and the like comprising, an lndex plate and a divided c1rstops, and two spring pressed jaws one in juxtaposition to each of said fixed stops whereby it will engage the movable stop and bring it into spring contact with its respective fixed stop.

6. In a zero and angle-setting attachment for theodolites and the like comprising, an index plate and a divided circle plate, two fixed stops adjustable on one of said plates and a bracket hinged to the other ot' said plates, a cam lever pivoted to said bracket,

a movable stop projecting from said lever to engage with said fixed stops, a spring engaging said lever and pressing the movable stop into operative relation with the fixed stops, a thumb piece to withdraw the movable stop out of operative relation with the fixed stops, spring pressed jaws in juxtaposition to the fixechjaws whereby the movable stop is brought into spring contact with the fixed stops, and a cam for controlling the movement of the spring pressed jaws.

WILLIAM GEORGE WIESENER.

Witnesses '1. C. ALLEN, HILDA GAUDER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. C. 

